This invention pertains to erasable labels generally and more specifically to labels for video cassettes, computer floppy disks, file folders, and the like where smear-proof erasable marking is desired.
Many items such as video cassettes, computer floppy disks, and file folders are re-used because the expense of disposing of the item is unacceptable. Video cassettes and computer floppy disks are specifically designed to be used over and over to record programs and data.
Since the contents of video cassettes and computer floppy disks cannot be viewed without the aid of a machine or device, labels are used to indicate the contents cassette or disk. Labels commonly available are affixed with adhesive and are non-removable. To change the marking on those labels, it is necessary to scratch out or write over the information. Alternatively, another label can be affixed over the original label. Where labels are removable, the label must be removed and discarded thereby adding to the expense of relabelling the item.
Several types of labelling means have been developed to overcome this problem. For example, U.S. Pat. No. 4,757,901, issued to Woods on July 19, 1988, describes an erasable label kit for video cassettes, computer disks, and the like which comprises self adhesive polyester film labels, a dry-erase marker pen, an erasing having polyester pile fabric, and a container for holding the labels, pen, and eraser. This provides for erasable labels but requires a special eraser. The eraser is prone to build up of the marking ink eventually resulting in incomplete erasure or smearing.
British Patent No. 2,190,631, issued to Weil on Nov. 25, 1987, describes an erasable label for attachment to video cassettes in which a two part window is attached to the cassette and the information is written onto two strips of material which generate an image when pressed together. Erasure is accomplished by separating the two strips with a cursor slid between the strips (a "magnetic slate" approach).
U.S. Pat. No. 4,589,685, issued to Lazar on May 20, 1986, describes a readily changeable labelling system employing a "magic slate" approach. The patent also describes an alternative embodiment which utilizes a protected easily erasable surface. The embodiment utilizing an easily erasable surface is based on a label formed from a slick plastic, vinyl, "Formica", porcelain enamel or other surface, and a standard felt tip pen or other erasable marker is used. Once the surface is written on, it is protected by a protective sheet (such as plastic) until it is to be erased.
U.S. Pat. No. 4,813,711, issued to Bohlman on Mar. 21, 1989, describes an index system which is cross-referenced to a permanent number printed on a blank cassette or other item to be marked. The entry on the index system is then erased and replaced when the program material is changed.
British Patent No. 2,055,702, issued to Squires on Mar. 11, 1981, describes a video-cassette box which has a pad on which information can be written and then erased. The pad includes an erasing arrangement of the "magic slate" kind by which the pad can be wiped clean partially or completely when the tape is recorded.
U.S. Pat. No. 4,884,827, issued to Kelley on Dec. 5, 1989, describes a partially transparent label for use on test tubes or collection tubes.
U.S. Pat. No. 4,507,883, issued to Tarrant on Apr. 2, 1985, describes a computer diskette labeling system using pressure sensitive labels. Identically coded labels are applied to the diskette and diskette jacket so that the correct diskette is returned to its corresponding jacket.
U.S. Pat. No. 4,674,771, issued to Thompson II on June 23, 1987, describes a pressure sensitive pharmaceutical label which cannot be removed with steam or water from a container once the label is applied.
Although the foregoing patents address some of the various needs of the industry, the devices and methods described in those patents do not provide for re-usable labels in which the identifying markings are smear-proof when touched by human hands and which can be erased with a damp cloth or paper towel.
The foregoing patents reflect the state of the art of which the applicant is aware and are tendered with the view toward discharging applicant's acknowledged duty of candor in disclosing information which may be pertinent in the examination of this application. It is respectfully stipulated, however, that none of these patents teach or render obvious, singly or when considered in combination, applicant's claimed invention.